It seems to me that prostitution is de facto largely treated this way in the U.S. In most cases, they don't arrest the johns or pimps but they do arrest the prostitutes. Technically, both are illegal but enforcement has a tendency to be one-sided. From what I gather, proving a pimp has committed a crime is much harder than proving a prostitute has and although the clients are also breaking the law in most U.S. states, they tend to get arrested a great deal less than the prostitutes. (Just what I've read over the years. No source to cite, no stats to back it up. Sorry.)
In most cases, a prostitute is forced to work as slave labor by the controlling pimp. That makes her the victim. Without customers to pull money in (the Johns), she would make no income for her pimp.
Once one instead follows the money, we realize that we can starve this trade by punishing the ones who have money (the Johns) and can dissuade prostitutes by making their somewhat forced career choice legal.
Not saying it's right, just that it's done. Routinely.
I'm not real political. I haven't studied it too thoroughly, so I am disinclined to make strong recommendations one way or the other. But I'm female and I have some difficulty wrapping my brain around the idea that a man can spend gobs of money on an expensive restaurant and movie and gifts to try to get into my pants but can't legally give me cash up front after asking nicely if I am amenable to such an arrangement. I generally think it would be best if prostitution were decriminalized. I am hesitant to speak to that overly much in public because my views on such topics tend to go over extremely badly with both genders.
Also, if I saw compelling data indicating that decriminalization would cause worse problems, I would be inclined to go with "whatever works for the greater good". However, I doubt I will see such data. Most studies are pretty poorly done. I find few of them all that compelling. For the moment, that leaves me with "This makes no sense to me." as a simple personal opinion.
Suffice it to say, if your recommendation could be implemented and did not turn out to have unexpected hidden social costs (in terms of causing problems), I would support it. With the proviso that I see no reason to actively try to dissuade prostitutes from making their living that way if they so choose. However, it would make it more feasible for them to change career paths if it were not illegal and I am for that. I have seen some things that indicate that difficulty in transitioning to other (legal) work is one of the things which keeps them trapped. Admitting you are a hooker doesn't exactly look good on a resume.
Your statement on prostitution is completely false, or at best very outdated. While it's a tangent to the main discussion, I feel obligated to correct it for the purpose of other people reading the comments.
The vast majority of prostitutes in the USA and similar countries are choosing the occupation of their own free will because it pays far better than alternatives. And a large fraction are now entirely independent, with no pimp or other structure involved. The "prostitutes are sex slaves" line is a myth propagated by organizations who would like you to believe this.
